1. Field of Invention
The present invention relates to an inkjet recording medium.
2. Related Art
The inkjet recording method is a recording method which is widely used not only in offices, but also in homes in consideration of merits such as that recording can be carried out on various recording media, equipment is relatively inexpensive and compact, and superior quietness.
Since resolution of ink jet recording apparatus (printers) has increased, obtaining high quality recorded materials which are comparable to silver halide photographs has become possible. However, in order to take full advantage of printer capabilities and obtain recorded materials having silver halide photograph-like high quality and preservation properties, recording media that are designed for exclusive use with ink jet are required. Examples of required characteristics for ink jet recording media include ink absorbability, coloring property, storability, suitability to conveyance in printers, glossiness, and surface smoothness.
Ink jet recording media having a porous structure in an ink-receiving layer have been developed for improving the various characteristics described above. Examples thereof include ink jet recording media having a porous layer which includes inorganic fine particles and a hydrophilic binder, and has a high void ratio, provided on a support (for example, see Japanese Patent Nos. 3561864, 4059356 and 3395882).
Examples of the hydrophilic binder include polyvinyl alcohols. Among polyvinyl alcohols, in particular, polyvinyl alcohols having a high degree of polymerization are used in view of suppressing layer cracking. When an ink-receiving layer liquid is prepared using a polyvinyl alcohol having a high degree of polymerization, since the liquid may have a high viscosity, there may be cases in which the liquid cannot be easily handled, which may make it difficult to apply the liquid to the support. In particular, when an ink-receiving layer liquid is formed by adding a polyvinyl alcohol to a dispersion liquid of inorganic fine particles, the viscosity of the liquid may become higher and handling of the liquid may be difficult. In view of addressing this, for example, Japanese Patent Application Laid-Open (JP-A) No. 2005-81645 discloses a recording layer coating liquid in which two polyvinyl alcohols having different average degrees of polymerization and different degrees of saponification from each other are used for improving the handling property.
When the content ratio of the hydrophilic binder in the ink-receiving layer is decreased in order to attain a high void ratio, the ink-receiving layer may become fragile, and, in particular, when an inkjet recording medium having such an ink-receiving layer is stored under low humidity conditions, fine cracks may occur on the surface of the ink-receiving layer. In view of addressing this, for example, JP-A No. 10-81064 discloses an inkjet recording paper in which two polyvinyl alcohols having different degrees of polymerization from each other are used.